Improvement in brakes for railway-carriages



3 Sheets-Sheet 1.

R. D. SANDERS. Brake for Railway Carriages.

No. 204,378. Patented May 28, 1878,

-FETERS, PHOTKLLITHOGRAPHER, WASHINGTON. D. C.

8 Sheets-Sheet 2.

R. D. SANDERS. Brakefor Railway Carriages.

No. 204,378. Patented May 28,1878.

3 Sheets-Sheet; 3.

R. D. SANDERS. Brake for Railway Carriages. No. 204,378.

Patented May 28,1878.

UNITED STATES PATENT OFFICE.

RICHARD D. SANDERS, OF BIRMINGHAM, ENGLAND.

IMPROVEMENT IN BRAKES FOR RAILWAY-CARRIAGES.

Specification forming part of Letters Patent No. 204,378, dated May 28,1878; application filed December patented in England, April 30, 1874,No. 1

522, and July 5, 1875, No. 2425; also in France, July To all whom it mayconcern:

Be it known that I, RICHARD DAVID SAN- DERs, of Birmingham, in thecounty of Warwick, England, mechanical engineer, have invented ordiscovered new and useful Improvements in Continuous Brakes forRailway-Garriages, which improvements are fully set forth in thefollowing specification, reference being had to the accompanyingdrawings.

My said invention consists principally of the improvements, hereinafterdescribed, and illustrated in the accompanying drawings, in working thecontinuous brakes of railwacarriages by means of two power-drums, havingflexible covers or diaphragms, the said power-drums being of differentdiameters. By means of an exhaust or vacuum in the said power-drums theexcess of atmospheric pressure on the drum of larger diameter over thatof smaller diameter causes the collapse of the flexible cover of theformer, by which collapse the brake mechanism is so operated upon thatthe brakes are held out of action. When the exhaust or vacuum isdestroyed in the power-drum of larger diameter, the exhaust or vacuuminthat of smaller diameter, being now free to act, draws the flexiblehead of the said smaller powerdrum inward, and so acts on the mechanismoperating the brakes that the blocks are forced against the wheels.

The exhaust or vacuum in the power-drums is produced by a steam-j et,ejector, or exhausting-pump, worked by the moving locomotive, or by thesteam of the locomotive-boiler, or otherwise. The power-drums areconnected together and to the exhausting apparatus by a pipe runningalong the train .of carriages, and the said pipe and power-drums areprovided with appliances, as hereinafter described, wherebytheexhaustion of both drums is maintained so long as the exhaust or vacuumis maintained in the connecting pipe, in which state of the power-drumsthe brakes are kept out of action. When, however, the vacuum isdestroyed in the pipe connected with the power-drums, either bytheopening of a valve or stop-cock, or the rupture of the said tube by aseparation of the carriages of the train, or otherwise, the exhaust inthe power-drum or larger diameter is destroyed, while that in the one ofsmaller diameter is preserved, and the brakes are brought into action.

The combination of power-drums described may be employed to workcontinuous brakes by means of compressed air instead of exhaust orvacuum.

Instead of using two power-drums of different diameters, a singlepower-drum may be employed, when the brakes are put into action byweighted levers or springs, the said single power-drum being employedonly for the pur pose of keeping the brakes off the wheels.

Figure 1 represents, in section, my arrangement for obtaining automaticaction by the use of two powerdrums of different diameters, acting inopposition to each other in the following manner: \Vhen the train is inmotion a constant vacuum is maintained in both the drums A B but inconsequence of the area of the drum A being greater than that of thedrum B, the pressure of the atmosphere, acting upon the flexible head Aof the drum A, overcomes that upon the flexible head of the drum B andbrings the lever F into the position shown in Fig. 1, in which positionof the lever the brakes are out of action. When air is admitted into thepipe along the train by the opening of a tap or valve on the engine orany of the carriages, or by an accidental separation of the train, thesaid air passes into the drum A an d destroys the vacuum therein; butthe said air is prevented from entering the drum B by a valve, G. Thedrum A being thus rendered powerless, the pressure of the atmosphere,acting upon the head B of the drum B, raises the said head, and with itthe bolt E, into the drum B, and thereby reverses the position of thelever F, as indicated in dotted lines in Fig. 1, and thus applies thebrakes, as hereinafter explained.

II is a reservoir, for the purpose of storing up a-vacuum or reservepower for maintaining the vacuum in the drum B. This reservoir may beomitted where the construction of the carriages will admit of thepower-drum B being made deeper and of increased capacity.

I is a cook or valve, for the purpose of dc stroying the vacuum orletting the pressure out of the drum B when it is required to releasethe brakes by hand.

Fig. 2 represents, inside elevation. and Fig.

3, in plan of under side, a railway-carriage to which the power-drums AB and the apparatus connected therewith (represented in Fig. 1) areapplied, K being the continuous pipe, and L the flexible coupling-pipesbetween the carriages.

By an examination of Fig. 2 it will be seen that thejbrake-meehanism isconnected with the lever F by means of the connecting-rods M M, andthat, when the said lever F is in the position represented, the brakesare taken out of action. It will be further understood, by anexamination of the said Fig. 2, that when the lever F takes the reverseposition, by the raising of the flexible head B of the powerdrum B, thedrawing inward of the connecting-rods M M causes the brake-blocks topress upon their respective wheels.

Thepower-drums,hereinbefore described and illustrated, may be used withcompressed air instead of a vacuum, if desired; but in that case thevalve G, Fig. 1, would have to be on the other side of its seat-that is,must open downward instead of upward.

Fig. 4 shows the application of one of the power-drums hereinbeforedescribed to brakes which are actuated or made to press upon the wheelseither by weighted levers or springs, or both. In this modification ofmy invention the exhaust in the single power-drum holds the brakes outof action; but when the exhaust in the power-drum is destroyed by theopening of the stop-cock or rupture of the train the brakes-are broughtinto action by the weighted levers or springs, or both.

In the said Fig. 4, I have represented one of the brakes as being madeto act upon the wheel by means of a coiled spring, a, acting on thelever b by means of the chain a passing overthe pulley d; and Ihaverepresented the said lever b as provided with a weight, 0, tendin g tomove it in the same direction as the springa; but it must be understoodthateither springs aalone maybe used, or weight-s0 alone may be used, orthat weights and springs in conjunction may be used.

f is the power-drum, the bolt 9 of which is connected at top to theflexible cover of the drum f, and at bottom is jointed to the lever b.The area of the flexible head of the powerdrum f is such that when thesaid drum is exhausted the atmospheric pressure upon it is largely inexcess of that required to counteract the pressure of the springs andweights a 0.

When, by the exhaustion in the powerdrum f, its flexible head and bolt 9are raised, the weighted end of the lever b is raised and thebrake-blocks withdrawn from the wheel. he exhaustion in the power-drum fbeing destroyed, the brake-blocks are brought into action by the springsa or weights 0, or both, as hereinbefore described.

The single power-drum f, Fig. 4, may be worked by compressed air insteadof by exhaust. In this case the drum f is placed on the other side ofthe axis h of the lever 12, so that the descent of the bolt 9 mayproduce the same motion of the lever b as is produced by the ascent ofthe said bolt y when in the position represented in the drawing.

My method of making the flexible heads of power-drums is represented inFig. 1.

A B are the flexible heads of the powerdrums A B, the said flexibleheadsconsisting of flexible covers, which are manufactured, in suitablemolds, to the form shown in the drawing. 0 O are center-plates betweenwhich the central portions of the flexible covers A B are grasped andsupported; and D is a ring, which secures the covering at the peripheryby means of screw bolts and nuts. By this method of constructing theflexible covers or heads A B of the power-drums, the centerplates 0 andthe said covers or heads A B and the bolts E E can be drawn inward or. I

outward without straining the covering, and the length of the strokes ofthe bolts E is in no degree dependent upon the elasticity of thematerial used for the coverings A B, but upon the amount of freedomgiven to them by the form adopted in their manufacture. By this methodof manufacture great durability is also secured in the coverings A B Themeans employed for maintaining the vacuum for the automatic actionconsists of an ordinary ejector, placed on some convenientpart of thelocomotive, and an exhaustingpump, worked from a reciprocating part ofthe engine or an eccentric. Before starting, the air is drawn out of thepipes and powerdrums by means of the ejector, and the vacuum is thenmaintained by the pump after the train is put in motion.

A separate donkey-pump may be used; but I prefer to work it from theengine. The exhaust-steam from the locomotive-cylinders may also be usedto workthe donkey-pump or the ejector.

Having now described the nature of my invention, and the manner in whichthe same is to be performed, I wish it to be understood that I claim asmy invention of improvements in continuous brakes for railway-earriages-The combination, with brakes and suitable mechanism to operate or pressthe same against the wheels of railway-carriages, of two power drums ofdifi'erent diameters, constructed and arranged, in relation to saidbrakes and intermediate mechanism, for operation in the manner hereinshown and described.

RIGHARD DAVID SANDERS. s.]

Witnesses:

Gnonen SHAW, RICHARD SKERRETT,

Of 37 Temple Street, Birmingham.

